Ball rolling apparatus



June 1, 1965 TAKEFUSA KlKUCHl 3,186,204

BALL ROLLING APPARATUS Filed April 4, 1963 s Sheets-Sheet 1 Mill".

INVENTOR. Takefiuso Kikuchi ATTORNEY June 1955 TAKEFUSA KIKUCHI 0 BALL ROLLING APPARATUS Filed April 1963 3 Shoots-Sheet 2 Luis.

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, INVENTOR. Tokefuso Kikuchi ATTORNEY June 1, 1965 TAKEFUSA KIKUCHI 3,186,204

BALL ROLLING APPARATUS Filed April 4, 1963 3 Sheets-Sheet 3 lllln INVENTOR. Tokefuso Kikuchi ATTORNEY United States Patent 3,186,204 BALL ROLLING APPARATUS Tairefusa Kikuchi, 372 3-chome, Musashino-shi Sakai, Tokyo-to, Japan Fiied Apr. 4, 1963, Ser. No. 279,711 Qlairns priority, appiication Japan, July 26, I962, 37/ 31,706 Claims. (Cl. 72-89) This invention relates to an apparatus for the manufacture of spherical balls most efficiently and economically with high accuracy out of a material bar by hot rolling.

conventionally, steel balls have been manufactured by die or stamp forging with such forging apparatus of a large size, such as drop hammers, crank presses or upsetting machines. In these forging processes, trimming machines are also necessary to cut off fins, which are inevitably generated between the joint of a pair of dies. The fins thus cut off, are then scrapped, causing loss of material. Moreover, the process requires skilled forging technique.

Thus the conventional methods of manufacturing spherical balls by forging are not only uneconomical, but also nonmassproductive, and result in high cost of production.

In order to eliminate the defects of forging presses as above mentioned, it is necessary to adopt a different method such as hot rolling.

This invention can eliminate all defects of conventional forging process and affords an efficient and precise ball rolling apparatus.

In the accompanying drawings, there are shown one or more of embodiments of the features of the invention. FIG. 1 is the front view, FIG. 2 is the side view of the ball rolling apparatus. FIG. 3 shows the sectional view along the line IIIIII in FIG. 1, FIG. 4, the sectional view along the line IV-IV in FIG. 3, FIG. 5, the developed sectional view along the line VV in FIG. 4, and FIG. 6 and FIG. 7, the sectional view along the line VI-VI and VII-VII respectively in FIG. 5. FIG. 8 shows how a round bar is rolled and changes to a ball.

FIG. 9-FIG. 12 show another embodiment of this invention. The description of this embodiment will be given later.

The rolling apparatus consists mainly of a pair of circular rolling discs 1 and 2, which have respectively a ridge 3 and 4, each being of a constantly increasing height and of a same shape and size as represented in FIGS. 3, 6 and 7. Each of these ridges forms a spiral of an equal form on the surface of the discs 1 and 2 as shown in the FIGS. 1, 3, 4 and 5. By each of the spiral ridges 3 and 4, a spiral groove 5 and a spiral groove 6 are formed respectively on the surfaces of the discs 1 and 2, as shown in FIGS. 2, 3, 4, 6 and 7.

The disc I and disc 2, which are rotatively supported concentrically through their respective axles 11 and 12, by their respective bearings 9 and It), are arranged so that the discs face parallel with each other as shown in FIG. 1, FIG. 2 and FIG. 3, and that the spiral ridges and grooves as above described to face with each other against the horizontal axis IIIIII as shown in FIG. 1.

The height of the spiral ridge 3 becomes gradually higher from its beginning point a on the circumference of the disc 1 to its maximum height b near the disc center and then maintains this height up to a point 0, the end of the spiral 3. The height of the spiral ridge 4 on the disc 2 is the same as that of the spiral ridge 3, while a, b and c on the ridge 4 correspond to a, b and c on the ridge 3 respectively.

The depth of the spiral grooves 5 and 6, formed by the spiral ridges of an increasing height h, becomes graduice ally deeper from a to b, as well as from a to b, and the shape of the cross section of the groove gradually changes from flat channel at and near the points a and a to a semicircle at the points b and b, where the ridges reach their maximum height.

From the point b or b to the end point C or C of the ridge, the shape of the groove is maintained semicircular in cross section, where the height of the ridge is kept constant at its maximum height.

The discs 1 and 2 with the spiral ridges 3 and 4 and the spiral grooves 5 and 6 respectively are placed face to face and parallel with each other as already described, so that the tips of the highest parts of ridges contact each other, and so that the ridges and circular grooves of two discs make a compiete circular tunnel at the rolling point.

The two discs 1 and 2, being so arranged as above described, are rotated at the same speed in the opposite direction by suitable rotating means 20, where disc I, as represented in FIG. 4, rotates counterclockwise and disc 2 rotates clockwise.

The axle 11 of the disc 1 is a hollow shaft having a hole 13 therethrough, as shown in FIGS. 2, 3 and 4, through which the rolled balls are discharged out of the apparatus.

The operation is as follows: a red heated bar 7 is inserted into the apparatus between the two discs, which are rotating in the opposite direction, as shown in FIGS. 1, 2 and 3.

Then the bar 7 is caught by the spiral ridges 3 and 4 at or near their beginning points a and a and at the same time a depression 8 begins to be indented, in the heated bar 7, and the bar is driven to rotate and is rolled between two discs by the ridges and grooves of the discs.

Thus, as the depression 8 is indented gradually deeper around the bar circumference by the spiral ridges forming a bar portion 7 which will further be rolled to a sphere, as shown in FIG. 8(1e), the bar is driven to shift towards the disc center.

FIG. 8(2b) shows the rolled state at the end of the 1st revolution of the discs.

When the discs begin their 2nd revolution, the ridges will catch the bar again at a and a, as in the first revolution, and a 2nd depression 8 begins to be indented, forming a 2nd bar portion 7 as shown by FIG. 8(2b), which shows the rolled state at the beginning of 2nd revolution. In the 2nd revolution, the depressions S and 8 are indented deeper by the ridges 3 and 4 of the revolving discs, till at last, at the end of 2nd revolution, the bar is rolled to a form as shown by FIG. 8(2e).

In this rolled state, shown in FIG. 8(2e), the 1st rolled portion '7 of the bar is rolled nearly to a sphere, and the 2nd portion 7 is rolled to the same shape as the 1st portion was rolled at the end of the 1st revolution as shown in FIG. 8(1e).

FIG. 8(3b) shows the rolled state of the bar, where the ridges have just gripped the bar and have begun to indent a 3rd depression 8 and to roll a 3rd portion 7 As the discs rotate further, the portions 7 7 and '7 are rolled further, and depressions 8 8 and 8 are indented deeper and deeper, till at last the 1st portion 7 reaches the :points b and b of the discs, where the ridges 3 and 4 become highest and the grooves 5 and 6 become semicircle in the cross section.

It is clear that at this point the 1st portion 7 will completely be rolled to a sphere by the ridges and grooves as above described, and will be separated from the bar 7, as shown in FIG. 8(3

The resultant rolled sphere 7 will then further be driven towards the centre and to be discharged out of the apparatus through the discharging hole 13, as shown in FIGS. 1, 2, 3 and 4.

Thus a ball is rolled and dischar ed out of the apparatus at every one revolution of the disc.

While a ball is rolled by an apparatus as above described, such apparatus has spiral ridges 3 and 4 which do not intersect the bar perpendicularly, and, as a result, the spiral ridges tend to force or pull the bar towards the disc centre in the course of rolling process.

FIGS. 9, 10, 11 and 12 show another embodiment of this invention which eliminate such pulling of the bar as described above. FIG. 9 is the front view, FIG. 10 is the side view, FIG. 11 is the sectional view along the line XIXI, and FIG. 12 shows the relative movement of a round bar and the apparatus as shown in FIGS. 9, 10, and 11, showing how the former is rolled by the latter.

In this device, the axles of the discs 1 and 2 are arranged to be eccentric with respect to each other. In the drawings, FIGS. 9, 10, 11 and 12, 0 and 0 0 being respectively the center lines of axles of the discs 1 and 2, are eccentrically located at a distance 6 from one another and are parallel with respect to each other; 0 0 is a straight line which lies between and at an equal distance 6/ 2 from the center lines and therefore is in one plane with these two centre lines.

The bar 7 is inserted between the discs 3 and 4, so that its longitudinal center line coincides with the straight line 0 0 These center lines 0 0 0 and 0 0 intersect the surface which contains the tip of the spiral ridge 3 at 0 0 and 0 respectively. Similarly these center lines 0 0 0 0 and 0 0 intersect another surface which contains the tip of the spiral ridge 4 at 0 0 and 0 (These 3 points are not shown in the drawings) But the tips of these two ridges are very close and touch each other at their highest regions, and therefore it may practically be assumed that these surfaces are plane, and that three points 0 0 and 0 coincide respectively with 0 0 and 0 in one plane.

P is the point of contact at which the spiral ridge 3 touches with the circumference of the bar 7; NN is a straight line parallel to the bar passing through the point of contact P; TT is a line normal to the line P0 p is the distance between the point 0 and the point of contact P; V is the peripheral speed of the bar 7 when the disc 1 rotates at an angular velocity (0 V and V are, respectively, the components of the velocity V towards directions T1 and NN; 0 is the angle between the velocity V and TI; P is the contacting point at which the bar 7 contacts the ridge 4 of the disc 2; and V; and V, V and V correspond respectively to V, V, and V of the point P as already described.

The process by which balls are rolled out of a bar by this apparatus will be explained with reference to FIG. 12 as follows.

The disc 1 rotates counterclockwise at angular velocity to around its center 0 and the disc 2 rotates around its center 0 clockwise at the same angular velocity.

Then the following relations will hold.

V= V= pw V..= v 92 and K v x tersect the ridges 3 and 4 perpendicularly by choosing properly the value of e, the eccentricity of two discs 1 and 2.

Thus, by the apparatus as above described, it is clear that after a bar is once inserted into the apparatus between the discs, the bar will be automatically rolled and shifted towards the center with no trouble, and will be gradually rolled and finally finished to a sphere at ever] revolution of the discs.

As described above, the apparatus as well as the process are very simple, and many finished balls may be rolled successively and automatically out of a heated bar, with high production efficiency, eliminating wastes in bar material, in heating, in labor and in the investment in the apparatus.

The halls thus manufactured are not only of high accuracy but also of super quality because the bar is gradually rolled to a finished ball without cutting its fibers. Therefore, the fibres structure of balls, which are thus rolled out of a bar with parallel fibre structure, becomes very nearly concentric around its center. Such fibre structure as symmetrical to the center is the ideal, which gives the best mechanical properties to a ball.

While the apparatus above described is a pair of discs, each of which having a set of a single spiral ridge and groove, it is, of course, possible to roll balls with discs having double spiral ridges and grooves.

The apparatus above described is adapted to roll spherical balls. It is also possible within the scope of the invention to provide apparatus with discs having spiral ridges and grooves of other shapes in cross section to roll pieces of any other surfaces of revolution.

I claim:

'1. An apparatus for roll forming balls, comprising a first circular disc having on its working surface a spiral ridge of gradually increasing height and decreasing Width from its periphery to the center thereof defining an adjacent spiral groove of gradually increasing depth and increasing width, a second circular disc positioned in facing relationship to said first circular disc, said second disc having the same size and shape as said first disc, means rotatively supporting said discs in facing spaced relationship so that the tips of the highest regions of said spiral ridges approach contact with each other, and means to rotate said discs in opposite directions at equal angular velocities.

2. An apparatus in accordance with claim 1 wherein the axes of rotation of said discs are eccentric.

3. An apparatus in accordance with claim 2 wherein said supporting axes are eccentric an amount equal to about one-third the diameter of the balls to be roll formed.

4. An apparatus in accordance with claim 1 wherein said spiral ridges begin at a point inside the periphery of said circular disks, said ridges having zero height at said periphery and a height equal to the radius of the balls to be roll formed at said tips of said highest regions of said spiral ridges, said tips just touching each other.

5. An apparatus in accordance with claim 4 wherein the width of said spiral ridges approach zero at said tips of said highest regions.

References Cited by the Examiner UNITED STATES PATENTS 385,186 6/88 Kempster -23 672,664 4/01 Bornemann 80--23 1,665,361 4/28 Hodge 80-23 1,691,248 11/28 Mun-r0 8023 1,746,671 2/30 Munro 8023 FOREIGN PATENTS 512,127 11/30 Germany.

CHARLES W. LANHAM, Primary Examiner. 

1. AN APPARATUS FOR ROLL FORMING BALLS, COMPRISING A FIRST CIRCULAR DISC HAVING ON ITS WORKING SURFACE A SPIRAL RIDGE OF GRADUALLY INCREASING HEIGHT AND DECREASING WIDTH FROM ITS PERIPHERY TO THE CENTER THEREOF DEFINING AN ADJACENT SPIRAL GROOVE OF GRADUALLY INCREASING DEPTH AND INCREASING WIDTH, A SECOND CIRCULAR DISC POSITIONED IN FACING RELATIONSHIP TO SAID FIRST CIRCULAR DISC, SAID SECOND DISC HAVING THE SAME SIZE AND SHAPE AS SAID FIRST DISC, MEANS RO- 